Small, handheld computing devices have been steadily growing in popularity in recent years. The devices go by different names, including, but not limited to, palmtops, pocket computers, personal digital assistants, personal organizers, handheld personal computers and ultramobile personal computers.
In general, handheld ultra-mobile personal computers are small, pocket-sized devices having an LCD (liquid crystal display) with a touch-sensitive screen, a stylus to enter data through the screen, and an input device such as a keypad or miniature QWERTY keyboard. Handheld ultra-mobile personal computers have a microprocessor, memory, and are capable of running an operating system and one or more applications on the operating system.
One of the most desirable characteristics of handheld personal computers is their portability. The compact, portable handheld ultra-mobile personal computers provide a user with real computer or computer-like applications, such as email, PIM (personal information management), an Internet browser, a spreadsheet, and word processing, and practically anything else that a user may do with a conventional personal computer. As examples, a user can receive email messages, schedule meetings or appointments, and browse the Internet from the handheld ultra-mobile personal computer.
Graphical user interfaces (GUIs) for computers are now common. They allow a user to graphically interact with a computer in a more intuitive and flexible manner when compared with command line interfaces (CLIs) or menu-driven interfaces. For example, one particularly popular graphical user interface is provided with the Microsoft Windows XP operating system. While graphical user interfaces work well on personal computers and laptop or notebook computers, some graphical user interfaces do not scale well to small displays such as those found on handheld devices like mobile phones, personal digital assistants (PDAs), and full fledged handheld personal computers.
For example, if a typical personal computer's graphical user interface was displayed on a PDA sized display (e.g., 5″ diagonal or less) screen, the text and icons would be too small to be legible (particularly for users who do not have good vision). In addition, navigating and usability within the graphical user interface can be difficult on a small screen. Even if the user is able to discern which icon represents the desired file or application, the icon may be so small as to make it difficult for the user to position the cursor over the icon (target).